Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
van hanh » ban hanh, van anh, van ban
dang xay » dang van, van xay
sach thu » sach thue, sach thieu, sach tham
te sach » toc sach
cac luc » cau luc, coc luc, cac nuoc
hieu ve » hieu va, hieu van
lang xa » lang ha, lang van
ve cac » va cac, vien cac
di cua » dai cua, doi cua, de cua
cua te » cua tu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te sach thu ((lang xa) OR (dang xay)) hoi. hieu ve cac luc ((van hanh) or (van thanh)) di cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach thu ((lang xa) OR (dang xay)) hoi. hieu ve cac luc ((van hanh) OR (van thanh)) di cua te.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach thu ((lang xa) OR (dang xay)) hoi. hieu ve cac luc ((van hanh) or (van thanh)) di cua te".
• Adding a wildcard symbol may retrieve word variants: te sach thu ((lang xa) OR (dang xay)) hoi. hieu ve cac luc ((van hanh) or (van thanh)) di cua te*.